Inspiron 546 Socket Type?

Assuming you order an Athlon X2 7750z in an Inspiron 546 does Dell use a Socket AM2+ motherboard (to match the AM2+ CPU) or a Socket AM2 since it's technically compatible but reduced performance?

Edit: Well, I talked to Dell and they say it's AM2+ (AMD 780 chipset, though they didn't specify which one, but I'd guess 780G).